Method of adhering green tape to a metal support substrate with a bonding glass
AssigneeDavid Sarnoff Research Center, Inc.
InventorsAshok N. Prabhu, Barry J. Thaler
Life of this patent
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Abstract
In the manufacture of ceramic circuit boards having ceramic or metal support substrates, a bonding glass layer that is adherent both to the substrate material and to multilayer green tape compositions having circuitry printed thereon, is deposited and flowed onto the support substrate. The bonding glasses suitable for use with nickel plated metal substrates and green tape compositions containing forsterite-cordierite-type glasses are mixed oxides including calcium, zinc and boron as well as other oxides. These bonding glasses have a thermal coefficient of expansion that is larger than said metal substrate, and a flow temperature below that of said cordierite-type glasses.
Claims12
A method of making a ceramic multilayer circuit board comprising a multilayer ceramic green tape stack made from forsterite-cordierite-type glasses having circuitry thereon and a ceramic or nickel plated metal support substrate comprising
- depositing a bonding glass on a surface of said support substrate, said bonding glass having a flow temperature and comprising an oxide mixture including calcium, zinc and boron oxides,
- patterning said bonding glass layer,
- aligning said coated support substrate with a multilayer green tape stack so that contact can be made between vias in said support substrate and the circuitry in said green tape stack, and
- firing the aligned coated substrate and green tape stack to a temperature above the flow temperature of the bonding glass so as to bond the resulting multilayer ceramic stack to said support substrate thereby limiting the shrinkage in the multilayer ceramic stack.
A method of making a ceramic multilayer circuit board comprising a multilayer ceramic green tape stack made from forsterite-cordierite-type glasses having circuitry thereon and a ceramic or nickel plated metal support substrate comprising
- depositing a bonding glass on a surface of said support substrate, said bonding glass having the composition of from 45-55% by weight of zinc oxide, from 30-40% by weight of boron oxide, from 3-7% by weight of calcium oxide and from 3-7% by weight of aluminum oxide, said bonding glass having a flow temperature,
- patterning said bonding glass layer,
- aligning said coated support substrate with a multilayer green tape stack so that contact can be made between vias in said support substrate and the circuitry in said green tape stack, and
- firing the aligned coated substrate and green tape stack to a temperature above the flow temperature of the bonding glass so as to bond the resulting multilayer ceramic structure to said support substrate.
Dependencies are inferred from the claim text.